1. Field
The present embodiment relates to an imaging apparatus including a primary filter and a pixel adding method thereof.
2. Description of the Related Art
In recent years, digital still cameras have been widely used that have the function of preventing the occurrence of camera shake by performing, at the time of shooting in a dark place, pixel addition in an image sensor to increase shooting sensitivity and thus a shutter speed. Digital video cameras have also been widely used that perform pixel addition in an image sensor to allow high-quality moving images to be taken at a high frame rate.
However, when the pixel addition (pixel mixing) is performed, a Nyquist frequency is lowered, with the result that moire (folding noise caused by a frequency component higher than the Nyquist frequency) is produced in the taken image.
In order to reduce the moire produced by the pixel addition, for example, in Japanese Unexamined Patent Application Publication No. 2008-98971, there is disclosed a method of performing pixel addition so that the centers of gravity of pixel groups of R, G, and B after the addition are evenly arranged without being unevenly distributed in the pixel region of an image sensor.
However, since a method of performing addition on the adjacent pixels of the same color is conventionally used, moire is still produced in a taken image, and there is room for improvements.